New Blank

General Discussion
21

yea your right on with those weights …

i just did some maths , i remember the lightest shortboard i built , back in 94 i had this red hot team guy …he was 57 kg , 120lb, i made him a 6’ x 18 x 2 1/8 …

it weighed 1.8 kg and that was with set fins , i just translated that to lb and its a shade under 4lb …

and back then we were hand laminating the outside , just like a conventional board ,plus using a polyester gloss coat , so a board that light is well within reach of the average board builder …i still own a 7lb longboard which i did in 96 which was hand laminated on the outside …

so basically , the concept is to offer a vacumn bagging service ???

and bag on any type of skin the customer might want ???

then give it back ready to laminate ???

this is how it looks to me …

customer picks up eps blank with parabolic stringers and outer p/u rail …

shapes blank and returns it to have outer skin bagged on …

then picks it up and goes off and does what he normally does …

greg im amazed how quick you picked up on the flex issue …

your absolutly right about the rigidity with having both sides sandwiched …

also you have to consider how much resin you allow to penatrate the core while bagging …if you lay up like your doing a normal board during the bagging process , all the excess will end up being drawn into the foam , it completly changes the way the foam flexes , it makes it real stiff and brittle …

you can still sandwich both sides , which gives a better overall durability , especialy around the fin area …

but with a thinner bottom sandwich and not allowing any resin to penatrate the core , youll still have the flex you want …using the .75 oz glass would definatly help with not allowing to much inner core penatration …

youll find with the flex thing as well , that moving the stringers closer to the rail , will allow a double sandwich board to still flex and move alot more , coz your allowing shear movement between the top and bottom of the board , where as the closer the stringer is to the centre the less shear movement you can have …

all the rules change in this game …

i bet some of the crew and yourself as well , are blown out by the performance lift you get from the construction concepts your working with now …

im stoked to see the type of stuff your doing …

i remember thinking to myself years back , it was like i opened a new door , but when i looked inside it was an endless corridor with more doors either side all the way into the distance …

i still havent opened all those inner doors , and ive been in here for a while …

a whole new world is opening up …the more crew who come in and explore , the better off every surfer will be in the future …

there are so many potential possible combinations of different materials you can sandwich together , to achieve a new level of performance …itll be like the mid 70s to mid 80s all over again , but instead of new shapes itll be new materials and constructions …

just what the industry needs to be reinvigourated …

welcome to the hotel california …

once you come in ,youll never want to leave …

regards

BERT

22

I’m using PU for the rails for a number of reasons. First, I can get it in 4# density which means I don’t need much glass on the rail for impact strength, which makes the glassing stage much easier. Second from a performance angle, the higher density rail allows you to sink the edge better giving more control and drive and it’s such a small volume that it doesn’t add much weight. Third, when combined with the balsa stringers and the outside glass you are creating a D - shaped structural member that goes around the entire board. D - shapes are what they use in wing spars in aircraft and are the strongest structural shape in nature. The foam, at 4# density, is structural in nature. Lower density foams, in the real world, aren’t considered structural and therefore are ineffective at handling stress loads leading to broken boards. Lots of good reasons there. It took a while to get a source for the PU at the density I was looking for and Walker came through.

Bert, From my perspective this doesn’t need to be bagged. Certainly there are advantages to doing it that way but what I wanted to engineer was a system that could be done in any exsisting shop. It’s funny, I built boards like this back in the 80’s too, but could never find the market willing to pay a bit more. We canned the whole thing and it just sat there in the back of my mind all those years. Interestingly I started looking at the construction again about a year and a half ago and then you popped up on this site. You certainly gave me a lot of insite and many short cuts along the way. I can only say thanks so much. I hope that between us we can make this sport go forward. We both know the advantages and like you said, there are a infinate number of doors to open. If everyone starts looking into all the doors we’ll get ahead that much faster.

23

My Hat is off to you on this one Greg.Finally something that really looks like it could be revolutionary.I like the fact that the average small factory could build this product without huge outlay of capitol for retooling.My thoughts are if you can get this deal rolling and produce a step by step video on how to do every step you may have a real winner. RB

24

greg …im not supposed to be here right now , i agree with everything in your last post … i gota get back in my shaping pit …

talk more later …great stuff

regards

BERT

25

Greg, does the deck of the board between the stringers have to be flat? I ask this for a couple of reasons. One being that with a sandwich construction, it would seem that the board would become more rigid as the dome of the deck was increased. With this, I would think that the stresses placed on the rail stringers and D-shaped structural reinforcements would be moved to the middle of the board, much like a conventional surfboard. Also, if the board has a domed deck, it would be a major pain in the ass to apply any kind of high-density foam to the deck without bagging. Thanks, -Carl

26

yea greg , i can see from my perpective youve found another one of those combinations that have a performance advantage …

its just like shaping , theres fors and againsts and give and take …

i can clearly see the advantages of what your doing and why you have come to the construction your at …you nailed the flex issue so quickly , only a surfer in a country with surf , with years of board building under his belt would have got that one so quick…you are so right about the D thing , ive found the same thing …nothing has more structual integrity…

i also completly agree with you on bottom movement and having more flex in the bottom than deck …

my very early sandwich boards with stringers were dogs , just to rigid , plus there was still the issue of the stringer protruding after some use , coz of the super light eps …i went for a double a few inches appart thinking it would help spread the load better , but it was a pain to shape where it hit the rail line , it just seemed to be a progression , that the skins got thinner to get the flex back , i ran wafer skins with no stringers , they were to flexy and rubbery , bad flex return , i folded one doing a bottom turn once …

i could keep going with all the variations , but certainly from what i know . i know your onto a winner , your slightly larger D section will give a slightly stiffer flex , which logically could only be offset by not running cored skins on both sides which gives the flex back , allowing the rails to become the real power zone ,

i posted a pic of a board ive had laying around for years , its one of the early ones when i was doing vents in the tail , the customer thought it was a drain plug , he had so many dings on his board , it looked like some one had chopped it with an ax , it would get water in every surf , he would go home and let it drain ???

i started putting the vents up front under the chest , so it was obvious , it wasnt a drain plug …

anyway i took it as a trade , cut the tail blocks off and let it drain properly , that was like a decade ago, i was fossicking around my retro collection the other day and i saw it , im gonna give it to my son to surf …when i saw your brochure , straight away it reminded me of the cross section of this board i was looking at a few days back , so i took a pic to show that i firmly believe your onto something …coz ive come to the same conclusions , and so far ive found nothing better yet , even tho the search continues constantly …

i keep coming back to this basic formula , even tho this is an old board , its not to far removed from what im doing now ,ive been churning this system out since about 91 , until i make an improvement or open that hidden door , it continues to be the best ive found …

thats why i have no problem backing what your doing straight away … as long as you get that deck skin to over lap your stringer or be attached to it very firmly your on a winner …

from your end you could probably see why ive gone in this direction , the pic is of the very last bit of tail , so it seems to look out of proportion coz of how close the camera was , but basically the D is alot smaller to allow more flex , coz of having a cored skin both sides, the bottom cored skin is thinner , the rails work in much the same way , but ive given a job to something else you cant see from here …

the horizontal stringer , we havent discussed that one yet …

from memory delbert was playing with something similar and getting great results ,put the parabola and the torsion bar together and youve got a power springboard that rides waves …

bustin down the doors …9,732 to go ,provided we dont come across any more hall ways

regards

BERT

27

Carl, the deck generally isn’t flat. It was just easier to do the schematic on the computer. As far as adding the deck laminate core, there are now a number of core materials that can be laminated without vaccuum bagging. Spheretex is the one we’ve used most but I’ve also used Coremat and a couple others. In Hatteras we’ve used some of the very thin scrimmed, scored material with success. We’ve also done some veneers and there is a technique for attaching those without bagging using a rolling pin. The biggest problem with all these has always been, what to do with the rails? Now that is solved.

Bert, I can see the advantages of moving the stringers but that pretty much takes planning. The goal here is to make this work within the framework of the standard surfboard industry so we have to comprimize a bit. As far as stiffness we also can change the resin modulus which changes the flex patterns of the finished board. Perhaps even a different resin on the bottom than you’d use on the deck. Oops, did I just open another hallway?

28

i reckon your on a winner and dont need to change anything …

your final product is sound , the slight differences in construction are offset by other slight differences …the comparisons i draw between our methods are only to highlight the obvious performance advantages of both , weighing up one facet against another to get that balance of a contolled smoothe ride …

so in the end i can see you have a good balance of flex and load bearing capability…

what youve come up with is a simple way of any board builder having access to the next level of construction technology , gaining the benifits of performance, lightness and durability, being able to compete with any of the higher tech stuff coming in …

in fact its better …

its better for a number of reasons …

1 it will out perform any of the imported moulded boards , coz of basic engineering principles , mainly in regard to flex , rate of flex return and shear movement …

2 it will out perform any of the imported moulded boards coz its not a moulded board…

i can forsee a snowball effect …

once crew start using the blanks , many may take the next step and just get a vac pump and start trying stuff , coz they would have been exposed to something new , they will have experienced the next level first hand , and will most likely draw inspiration from it …

the possible combinations are many …

exciting times …

regards

BERT

29

Very innovative and exciting–when will they be available for use?

30

Can’t wait to see the new blanks with balsa. I hope they will be available out of Indialantic too.

I’ve been mulling over the whole parabolic thing and marveling over the simplicity and all many problems with blanks that get solved with this new technology of yours.

Regarding Bert’s comment about extending the core material across the balsa stringer, you could avoid the need to do that by adding another strip of 4 pound foam 1/2 inch wide inside of the stringer but not quite as tall as the stringer to allow a place to bond the core to. That way the balsa stringers could show. Downside is that it adds another construction step.

I don’t have access to balsa in lengths that would serve for stringers, but I would like to have a whack at the parabolic thing with carbon. In the vein of experimentation and what might have a reasonable chance of success, what do you think about cutting the parabolic shape in a standard EPS blank and inserting a 6-inch strip of epoxy saturated carbon fiber tape? Then clamp it back together and shape as usual. Could be a little hard on the planner, but oh well. Maybe start with a 1 pound EPS blank and add 2 pound EPS rails? Maybe add carbon tape on the outside of the rails to make up for the lower density foam? I’m tinkering with cut-lap carbon in test patches and feeling encouraged.

31

Greg- very exciting looking stuff! Can’t wait to see what comes of this and what makes it to the market (written while while repairing, yet again, another of my PU boards that took a light tap from my shin and now requires extensive surgery!).

32

well ive had a good think about it …

and ive decided to fess up … and let you look inside a light later model board …

even tho it kinda looks bad , the reality is my boards still break as well , even tho my snappage rate is 1/10th that of a normal board , which reflects in data i recorded a few years back as well …

i didnt actually break this board … it was mine , i loved it … ive included a set of sequence pics of me riding it as well ,so you can see how much spring and acceleration it has off nothing …

anyway i leant it to a guy to take to the national titles this year , i couldnt go coz of family commitments …he brought it back like this , he said "if its any consolation , it was a thumper of a wave that landed on it while i was in the impact zone " some one else told me the story as well … reckons it was hell funny , coz 2 guys were caught inside and the same wave broke both there boards , and so there they were both wallowing around in the zone with snapped boards …

anyway … the basic principle is this …

get a paper back book and bend it , see how all the pages slide past each other to accomadate the new curve …

when you put a stringer in a board and connect the top to the bottom, you stop shear movement … so now when the board is put under load something has gota give …

the horizontal free floating stringer allows the board to really flex and twist , but gives added spring , adjusting the width and thickness of the bar allows you to dial in flex …

i wanted lighter and lighter boards , get to a certain point and lightness becomes rubberyness and also weakness ,you can go thicker sandwich , but that just adds stiffness without spring … the horisontal stringer allows me to go irresponsibly light (this board was 9’-2" x 24 x 2 5/8 it weighed 4kg or just under 9lb ) but still have spring , the board can bend and just like the pages of the book , can tolerate shear movement without stressing anything out , the bar works harder the more load you put on it , the closer it is to the neutral axis the better it works , you can even move it around for flex bias …

since ive been coming to swaylocks , ive realised that the length of time ive been doing this type of stuff has given me a clear jump … so i kinda feel now , that its pointless keeping all this stuff to my self …because over the years people have bagged what im doing with no real appreciation of what i actually am doing …

so this is kind of my attempt to at least claim my own work …its pained me over the years to see big companies step out and develop variations of stuff i had developed , without even a hint of recognition about where they drew inspiration …at least i can post stuff here knowing its going to a good cause , and become public property , before some sleazy just for profit, milk the surfing scene company , trys to pull some , we own it now coz we got all the lawyers trick …plus when i see people like greg and his willingness to share , and his honest approach to just wanting to make better surfboards , that inspires me , coz thats why i do it to …also ive got so many boards to build , i figure id rather see work go to crew out there in swaylocks land , rather than seeing cash go to asian board buying agents …

this system allows a board to flex in a more natural way … back when i had a foray into xtr … i was building boards by pressing 2 sheets of 30mm iso foam together , routing out a groove in one piece laying the stringer in and pressing it like a skateboard deck … it looks like a stringerless board it shapes like a stringerless board

you get a joinline around the apex from your glue line thats it …only thing is it performs better than a conventional stringered board …

its just xtr is such crappy foam ,i was thinking about building p/u boards this way …

but i cant do it …same thing its just not durable enough , even if it would perform a little better than the norm …

so here it is … the floating horizontal stringer …

and me riding it …

and back to the lip

wo , that was different …

regards

BERT


33

Bert…you rock.

I started building boards this year after visiting 2 shapers. I watched Mike Eaton mow EPS and watched Ole work with wood. I realized I could use my carpentry background and ding repair expeirence to do both.

I can honestly say you are the main guy leading me and insipring me to the next level of board building sophistication. Your innovation and willingness to share are peerless. Thank you.

Ben

edit: don’t want to leave anyone out, either; G Loehr, J Phillips, and all the ‘pros’ who share their secrets; Haaavard, Schwuz, Chipfish, and all the non-paid pros who share their innovations. Its an amazing community, really.

34

Bert,

I’ll second Benny’s thoughts. Your post have inspired many stray thoughts to materiallize in my head. Now either I need to start building or working :).

Looks like my son may be getting a horizontal stringer.

thanks for your contributions Bert, and while we are at it, Gregg and everyone else too. Swaylock’s has changed my whole surfing experience.

thanks

35

i figure id rather see work go to crew out there in swaylocks land , rather than seeing cash go to asian board buying agents … me too but be carefull of the internet… its working in the east too bert! too many new innovations are quickly copied and refined…

36

Thank you Bert. Great stuff.

This is like the sandwich-stringer GL described recently, but not anchored to the skin.

Love the idea and the applications makes great sense… as you’ve shown.

Like a hunting bow in a bag of EPS, glassed.

questions

  • Best with EPS because of it’s springyness/more memory?

  • you also have the wood skin and rails going on these, right? Would I need more ‘shell’ than just epoxy and glass? It would seem this would walk a line between just enough springy flex and easy delamination. Am I warm?

  • how does one dial in the stringer thickness?

Brains moving,

Thanks again,

Eric J

37

Hey Bert,

Watchout 'cause the asian internet trolls will copy your idea.

But could you tell me how to do it and post some pictures because I really don’t want to take the 15 steps out to the garage and do the work myself…

You’re the best…

38

Bert,

Is your horizontal stringer installed with the same curve as your rocker, straight along the board’s center line, or curved opposite to the rocker?

39

You rock Bert - you and Greg are taking swaylocks to the next level. Love it. I was just re-reading “Understanding Aircraft Composite Construction” by Zeke Smith, trying to get inspired. The farthest I got was mulling over a horizontal stringer attached to the deck-side sandwhich. The floating stringer is ingenius.

40

hey greg…

i know your working on getting your epoxy to hawaii, any chance that we’ll get a shot at the blanks too?